Soalr energy water heater

ABSTRACT

A solar energy water heater includes a water pipe and a plurality of solar heat units transversely extended from the water pipe, wherein each solar heat unit includes a heat collecting tube is adapted for heating up the water within the heat collecting tube and a heat transferring tube disposed in the heat collecting tube to define a water conduit. The heat transferring tube has a water channel and an outer opening end extended towards to an outer closed end of the heat collecting tube to communicate the water channel with the water conduit of the heat collecting tube such that the water is guided to flow from the water inlet to each of the solar heat units to circularly flow between the water conduit and the water channel thereof so as to substantially heat up the water before flowing out at a water outlet of the water pipe.

BACKGROUND OF THE PRESENT INVENTION

1. Field of Invention

The present invention relates to a water heater, and more particularlyto a solar energy water heater, wherein the water is guided tocircularly flow within each of heat collecting tubes to substantiallyheat up the water therewithin by solar energy while being costeffective.

2. Description of Related Arts

Conventional water heaters mainly utilize gas or electricity as a powersource to heat up water for domestic or industrial purpose. Aconventional water heating system comprises a water heater having awater outlet and a water inlet connecting with a water source in such amanner that the water at the room temperature is heated up by the waterheater to reach a preset temperature.

Water heater utilizing solar energy as the power source has beendeveloped to resolve the problems of potential energy crises orshortages. Those solar energy water heaters no doubt meet theever-increasing demand of environmental protection and ‘clean energysource’ from people all over the world. Yet they have several drawbacks.

The solar energy water heater comprises a heat collecting tube defininga water passage therein wherein water is guided to flow into the heatcollecting tube in such a manner that the heat collecting tube collectsthe solar energy and heats up the water within the water passage.Accordingly, the heat collecting tube is made of glass coated with asolar heat absorbing layer such that when the heat collecting tube isexposed under the sunlight, the solar heat absorbing layer absorbs thesolar energy and transfers into the water passage to heat up the watertherewithin. It is worth to mention that the hot water is collected atthe upper portion of the heat collecting tube to a water tank while thecool water is remained at the lower portion of the heat collecting tubesuch that the efficiency of the conventional solar energy water heateris very low.

Furthermore, the water system cannot be normally functioned during theheat exchange of the water. In other words, when using the hot water inthe water tank, a valve of the solar energy water heater is closed tostop the water to enter into the heat collecting tube. Therefore, thesolar energy water heater cannot be functioned under the normal waterpressure of the water system since the water must be collected withinthe heat collecting tube for heat exchange.

In addition, the heat collecting tube, having an upper opening end and abottom sealing end, must be positioned in an inclined manner that thewater is guided to flow into the water passage at an upper opening endof the heat collecting tube. Once the water is heated up, the hot waterflows out of the heat collecting tube at the upper opening end thereofwhile cool water is filled towards the bottom sealing end. Therefore,the installation of the solar energy water heater is limited by theposition of the heat collecting tube that the heat collecting tube mustbe located at an optimized orientation under the sunlight. It is worthto mention that the temperature of the heat collecting tube isrelatively high in order to heat up the water therewithin such that whenthe cool water is filled into the heat collecting tube, the glass madeheat collecting tube will be cracked due to the sudden change oftemperature. In other words, the manufacturer should take account of thequality of the heat collecting tube to prevent the crack thereof whichwill highly increase the manufacturing cost of the solar energy waterheater. Once the heat collecting tube is broken, the entire solar energywater heater cannot be functioned.

SUMMARY OF THE PRESENT INVENTION

A main object of the present invention is to provide a solar energywater heater, wherein the water is guided to circularly flow within eachof the heat collecting tubes to substantially heat up the watertherewithin by solar energy while being cost effective.

Another object of the present invention is to provide a solar energywater heater, wherein the heat collecting tubes are radially extendedfrom a water pipe such that the water flows from a water inlet of thewater pipe to a water outlet thereof through each of the heat collectingtubes to enhance the heat exchange process.

Another object of the present invention is to provide a solar energywater heater, wherein the water system can be normally function duringthe operation of the solar energy water heater because the water flowsinto the water pipe at the water inlet and out of the water pipe at thewater outlet normally under the water pressure of the water system.

Another object of the present invention is to provide a solar energywater heater, which can be located at any position to optimize the sunorientation for effectively transforming solar energy into heat energy.

Another object of the present invention is to provide a method ofheating water by solar energy while being cost effective.

Another object of the present invention is to provide a solar energywater heater, which does not involve complicated mechanical componentsso as to minimize the manufacturing cost and the ultimate selling priceof the present invention.

Accordingly, in order to accomplish the above objects, the presentinvention provides a solar energy water heater, comprising:

a water pipe having a water inlet and a water outlet and defining awater passage therebetween for guiding water to flow from the waterinlet to the water outlet; and

a plurality of solar heat units transversely and spacedly extended fromthe water pipe to communicate with the water passage thereof, whereineach of the solar heat units comprises:

a heat collecting tube having an outer closed end and an inner openedend extended from the water pipe, wherein the heat collecting tube isadapted for collecting solar energy and transforming the solar energyinto heat energy to heat up the water within the heat collecting tube;and

a heat transferring tube, which is made of heat conductive material,disposed in the heat collecting tube to define a water conduit betweenthe heat collecting tube and the heat collecting tube, wherein the heattransferring tube has a water channel and an outer opening end extendedtowards to the outer closed end of the heat collecting tube tocommunicate the water channel with the water conduit of the heatcollecting tube such that the water is guided to flow from the waterinlet to each of the solar heat units to circularly flow between thewater conduit and the water channel thereof so as to substantially heatup the water at each of the solar heat units before flowing out at thewater outlet of the water pipe.

These and other objectives, features, and advantages of the presentinvention will become apparent from the following detailed description,the accompanying drawings, and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a solar energy water heater according to afirst preferred embodiment of the present invention.

FIG. 2 is a sectional view of the solar heat unit of the solar energywater heater according to the above first preferred embodiment of thepresent invention.

FIG. 3 is a schematic view of a solar energy water heater according to asecond preferred embodiment of the present invention.

FIG. 4 is a schematic view of the solar heat unit of the solar energywater heater according to a third preferred embodiment of the presentinvention.

FIG. 5 is a partially exploded perspective view of the solar energywater heater according to the above third preferred embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1 of the drawings, a solar energy water heateraccording to a first preferred embodiment of the present invention isillustrated, wherein the solar energy heater comprises a water pipe 10and a plurality of solar heat units 20.

The water pipe 10 has a water inlet 11 and a water outlet 12 and definesa water passage 13 therebetween, wherein the water pipe 10 isoperatively communicating with a water source S such that water from thewater source S flows into the water pipe 10 at the water inlet 11 andflows out at the water outlet 12. A heat insulating layer 14 isenclosing an outer surface of the water pipe 10 for preventing heat lossof the water passing along the water passage 13. In other words, thewater pipe 10 not only guides the water to flow to each of the solarheat units 20 but also conserves the heat energy of the water when thewater is heated up by the solar heat units 20.

The solar heat units 20 are transversely and spacedly extended from thewater pipe 10 to communicate with the water passage 13 thereof, whereineach of the solar heat units 20 comprises a heat collecting tube 21 anda heat transferring tube 22.

Each of the heat collecting tubes 21 has an outer closed end 211 and aninner opened end 212 extended from the water pipe 10, wherein the heatcollecting tube 21 is adapted for collecting solar energy andtransforming the solar energy into heat energy to heat up the waterwithin the heat collecting tube 21.

Each of the heat transferring tubes 22, which is made of heat conductivematerial such as copper, disposed in the respective heat collecting tube21 to define a water conduit 210 between the heat collecting tube 21 andthe heat collecting tube 22, wherein the heat transferring tube 22 has awater channel 220 and an outer opening end 221 extended towards to theouter closed end 211 of the heat collecting tube 21 to communicate thewater channel 220 with the water conduit 210 of the heat collecting tube21 such that the water is guided to flow from the water inlet 11 to eachof the solar heat units 20 to circularly flow between the water conduit210 and the water channel 220 thereof so as to substantially heat up thewater at each of the solar heat units 20 before flowing out at the wateroutlet 12 of the water pipe 10.

As shown in FIG. 1, each of the solar heat units 20 is perpendicularlyextended from the water pipe 10 at a direction wherein the water isguided to flow from the water inlet 11 to each of the solar heat units20 for heat exchange and to flow out at the water outlet 12.

As shown in FIG. 2, each of the heat collecting tube 21 comprises anouter tubular member 213, an inner tubular member 214 sealed therein inend-to-end manner, and a solar energy collecting agent 215 sealedlyprovided between the outer and inner tubular members 213, 214, whereinthe water conduit 210 is formed between the inner tubular member 214 andthe heat transferring tube 22 receiving therein such that the solarenergy collecting agent 215 is adapted for collecting the solar energyto heat up the water within the inner tubular member 214. Preferably,each of the outer and inner tubular members 213, 214 is made of glassadapted for the sunlight passing therethrough to reach the solar energycollecting agent 215.

Each of the heat transferring tubes 22 is made of heat conductivematerial, such as copper, such that the heat energy from the respectiveheat collecting tube 21 is adapted to conductively transfer into thewater channel 220 through the heat transferring tube 22 for heating upthe water within the water channel 220. In other words, the water withineach of the solar heat units 20 is heated up twice at the time when thewater pass through the water conduit 210 and the water channel 220. Itis worth to mention that when the cool water suddenly flows to the heatcollecting tube 21 which is relatively hot, the heat collecting tube 21may be cracked due to the sudden change of temperature. Therefore, thewater is preheated along the heat transferring tubes 22 to prevent thecrack of the heat collecting tube 21 when the water flows to the waterconduit 210.

The solar energy heater further comprises a plurality of water guiders30 spacedly disposed in the water passage 13 of the water pipe 10 toalign with the solar heat units 20 respectively, wherein each of thewater guiders 30 has a guiding passage 31 extended to an inner end 222of the respective heat transferring tube 22 for guiding the water toflow into the water channel 220 from the water passage 13 such that thewater flows to the water conduit 210 from the water channel 220 throughthe outer opening end 221 of the heat transferring tube 22 and back tothe water passage 13 of the water pipe 10 through the inner opened end212 of the solar collecting tube 21, as shown in FIG. 1.

In other words, the water from the water source flows into the waterinlet 11 of the water pipe 10 through each of the solar heat units 20and exits at the water outlet 12 of the water pipe 10. Accordingly, thewater is guided to flow into the water channel 220 of the respectiveheat transferring tube 22 via the water guider 30 to the water conduit210 of the respective heat collecting tube 21 when the water flows toeach of the solar heat units 20, such that the water can besubstantially heated up twice at each of the solar heat units 20.

It is worth to mention that the solar energy water heater of the presentinvention can be incorporated with the conventional water system havinga predetermined water pressure such that the water at the water source Sis pumped to the water pipe 10 at the water inlet 11 to each of thesolar heat units 20. In addition, the solar energy water heater of thepresent invention can be incorporated with the conventional water systemwithout water pressure, such that the water flows from the water inlet11 to the water outlet 12 through each of the solar heat units 20 bygravity. In other words, the water flows from the solar heat unit 20 atthe upper position to the solar heat unit 20 at the bottom position bygravity. Furthermore, the user is able to select how many the solar heatunits 20 is needed to heat up a predetermined volume of water for usage.Therefore, the user can set up the solar energy water heater by simplyassembling the solar heat units 20 to the water pipe 10. In other words,even one of the solar heat units 20 is broken, the solar energy waterheater can still properly function and the user is able to replace thebroken solar heat units 20 as well.

As shown in FIG. 3, a solar energy water heater of a second embodimentillustrates an alternative mode of the first embodiment of the presentinvention, wherein the solar heat units 20′ are formed in pairs and aretransversely and spacedly extended from the water pipe 10′ tocommunicate with the water passage 13′ thereof. Each of the solar heatunits 20′, having the same structure of the first embodiment, comprisesa heat collecting tube 21′ and a heat transferring tube 22′.

The water pipe 10′ is operatively communicating with a water source Ssuch that water from the water source S flows into the water pipe 10′ atthe water inlet 11′ and flows out at the water outlet 12′. A heatinsulating layer 14′ is enclosing an outer surface of the water pipe 10for preventing heat loss of the water passing along the water passage13′.

Each of the heat collecting tubes 21′ has an outer closed end 211′ andan inner opened end 212′ extended from the water pipe 10′, wherein theheat collecting tube 21′ is adapted for collecting solar energy andtransforming the solar energy into heat energy to heat up the waterwithin the heat collecting tube 21′. Accordingly, each of the heatcollecting tube 21′ comprises an outer tubular member, an inner tubularmember and a solar energy collecting agent as shown in FIG. 2.

Each of the heat transferring tubes 22′, which is made of heatconductive material, disposed in the respective heat collecting tube 21′to define a water conduit 210′ between the heat collecting tube 21′ andthe heat collecting tube 22′, wherein the heat transferring tube 22′ hasa water channel 220′ and an outer opening end 221′ extended towards tothe outer closed end 211′ of the heat collecting tube 21′ to communicatethe water channel 220′ with the water conduit 210′ of the heatcollecting tube 21′ such that the water is guided to flow from the waterinlet 11′ to each of the solar heat units 20′ to circularly flow betweenthe water conduit 210′ and the water channel 220′ thereof so as tosubstantially heat up the water before flowing out at the water outlet12′ of the water pipe 10′.

As shown in FIG. 3, the solar heat units 20′ are formed in pair whereineach pair of the solar heat units 20′ are opposedly extended from thewater pipe 10′ to communicate with the water passage 13′ thereof.Accordingly, the water is guided to flow from the water inlet 11′ to thewater outlet 12′ through each pair of the solar heat units 20′ in azigzag manner.

According to the second embodiment, the two heat transferring tubes 22′of each pair of the solar heat units 20′ are integrally extended to forman elongated tubular structure through the water pipe 10′ so as tocommunicate the water channels 220′ with each other such that the wateris guided to flow to each pair of the solar heat units 20′ in a zigzagmanner that the water flows into the water conduit 210′ of one of thesolar heat units 20′ from the water pipe 10′ and then flow into thewater channels 220′ to another solar heat unit 20′ so as to return backto the water pipe 10′ through the water conduit 210′ of the respectivesolar heat unit 20′, as shown in FIG. 3.

The solar energy water heater further comprises a plurality of waterguiders 30′ spacedly disposed in the water passage 13′ of the water pipe10′ to align with the pairs of solar heat units 20′ respectively,wherein each of the water guiders 30′ has a guiding passage 31′ extendedto the inner opened end 212′ of the respective heat collecting tube 21′for guiding the water to flow into the respective water conduit 210′such that the water flows to the water channel 220′ from the waterconduit 210′ through the outer opening end 221′ of the heat transferringtube 22′ and back to the water passage 13′ of the water pipe 10′ fromthe water conduit 210′. Therefore, the water circularly flows withineach of the solar heat units 20′ to substantially heat up the watertherewithin by solar energy.

As shown in FIG. 4, a solar energy water heater of a third embodimentillustrates an alternative mode of the second embodiment of the presentinvention, wherein the solar heat units 20″ are formed in pairs and aretransversely and spacedly extended from the water pipe 10″ tocommunicate with the water passage 13″ thereof. Each of the solar heatunits 20″, having the same structure of the first embodiment, comprisesa heat collecting tube 21″ and a heat transferring tube 22″.

The water pipe 10″ is operatively communicating with a water source Ssuch that water from the water source S flows into the water pipe 10″ atthe water inlet 11″ and flows out at the water outlet 12″. A heatinsulating layer 14″ is enclosing an outer surface of the water pipe 10″for preventing heat loss of the water passing along the water passage13″.

Each of the heat collecting tubes 21″ has an outer closed end 211″ andan inner opened end 212′ extended from the water pipe 10″, wherein theheat collecting tube 21″ is adapted for collecting solar energy andtransforming the solar energy into heat energy to heat up the waterwithin the heat collecting tube 21″. Accordingly, each of the heatcollecting tube 21″ comprises an outer tubular member, an inner tubularmember and a solar energy collecting agent as shown in FIG. 2.

Each of the heat transferring tubes 22″, which is made of heatconductive material, disposed in the respective heat collecting tube 21″to define a water conduit 210″ between the heat collecting tube 21″ andthe heat collecting tube 22″, wherein the heat transferring tube 22″ hasa water channel 220″ and an outer opening end 221″ extended towards tothe outer closed end 211″ of the heat collecting tube 21″ to communicatethe water channel 220″ with the water conduit 210″ of the heatcollecting tube 21″ such that the water is guided to flow from the waterinlet 11″ to each of the solar heat units 20″ to circularly flow betweenthe water conduit 210″ and the water channel 220″ thereof so as tosubstantially heat up the water before flowing out at the water outlet12″ of the water pipe 10″. It is worth to mention that when the coolwater suddenly flows to the heat collecting tube 21″ which is relativelyhot, the heat collecting tube 21″ may be cracked due to the suddenchange of temperature. Therefore, the water is preheated along the heattransferring tubes 22″ to prevent the crack of the heat collecting tube21″ when the water flows to the water conduit 210″.

As shown in FIG. 4, the solar heat units 20″ are formed in pair whereineach pair of the solar heat units 20″ are opposedly extended from thewater pipe 10″ to communicate with the water passage 13″ thereof.Accordingly, the water is guided to flow from the water inlet 11″ to thewater outlet 12″ through each pair of the solar heat units 20″ in asplitting manner that the water is divided evenly to flow to the solarheat units 20″.

The solar energy water heater further comprises a plurality of waterguiders 30″ spacedly disposed in the water passage 13″ of the water pipe10″ to align with the pairs of solar heat units 20″ respectively,wherein each of the water guiders 30″, having a T-shape, has two guidingpassages 31″ extended to two inner ends 222″ of the heat transferringtubes 22′ respectively for guiding the water to flow into the waterchannels 220″ such that the water flows to the water conduits 210″ fromthe water channels 220″ through the outer opening ends 221″ of the heattransferring tubes 22″ respectively and back to the water passage 13″from the water conduits 210″, as shown in FIG. 5.

Accordingly, each of the water guiders 30″ has a guiding splitter 32″disposed within the water passage 13″ for evenly dividing the watertherewithin into two portions to flow into the respective pair of solarheat units 20″. In other words, the two portions of the water circularlyflow within each pair of solar heat units 20″ to substantially heat upthe water therewithin by solar energy.

According to the third embodiment, the water pipe 10″ comprises aplurality of tubular bodies 101″ coaxially mounted with each other toform the water passage 13″ wherein each of the tubular bodies 101″ ispositioned between each pair of the solar heat units 20″ such that thesolar energy water heater of the present invention is adapted to beeasily assembled or disassembled for transportation and storage.

One skilled in the art will understand that the embodiment of thepresent invention as shown in the drawings and described above isexemplary only and not intended to be limiting.

It will thus be seen that the objects of the present invention have beenfully and effectively accomplished. It embodiments have been shown anddescribed for the purposes of illustrating the functional and structuralprinciples of the present invention and is subject to change withoutdeparture from such principles. Therefore, this invention includes allmodifications encompassed within the spirit and scope of the followingclaims.

1. A solar energy water heater, comprising: a water pipe having a waterinlet and a water outlet and defining a water passage therebetween forguiding water to flow from said water inlet to said water outlet; and aplurality of solar heat units transversely and spacedly extended fromsaid water pipe to communicate with said water passage thereof, whereineach of said solar heat units comprises: a heat collecting tube havingan outer closed end and an inner opened end extended from said waterpipe, wherein said heat collecting tube is adapted for collecting solarenergy and transforming said solar energy into heat energy to heat upsaid water within said heat collecting tube; and a heat transferringtube, which is made of heat conductive material, disposed in said heatcollecting tube to define a water conduit between said heat collectingtube and said heat collecting tube, wherein said heat transferring tubehas a water channel and an outer opening end extended towards to saidouter closed end of said heat collecting tube to communicate said waterchannel with said water conduit of said heat collecting tube such thatsaid water is guided to flow from said water inlet to each of said solarheat units to circularly flow between said water conduit and said waterchannel thereof so as to substantially heat up said water at each ofsaid solar heat units before flowing out at said water outlet of saidwater pipe.
 2. The solar energy water heater, as recited in claim 1,further comprising a plurality of water guiders spacedly disposed insaid water passage of said water pipe to align with said solar heatunits respectively, wherein each of said water guiders has a guidingpassage extended to an inner end of said respective heat transferringtube for guiding said water to flow into said respective water channelfrom said water passage such that said water flows to said respectivewater conduit from said water channel through said outer opening end ofsaid heat transferring tube and back to said water passage of said waterpipe through said inner opened end of said solar collecting tube.
 3. Thesolar energy water heater, as recited in claim 2, wherein said solarheat units are perpendicularly extended from said water pipe at adirection such that said water is guided to flow from said water inletto each of said solar heat units for heat exchange and to flow out atsaid water outlet.
 4. The solar energy water heater, as recited in claim1, wherein each of said heat collecting tube comprises an outer tubularmember, an inner tubular member sealed therein in end-to-end manner, anda solar energy collecting agent sealedly provided between said outer andinner tubular members, wherein said water conduit is formed between saidinner tubular member and said heat transferring tube such that saidsolar energy collecting agent is adapted for collecting said solarenergy to heat up said water within said inner tubular member.
 5. Thesolar energy water heater, as recited in claim 3, wherein each of saidheat collecting tube comprises an outer tubular member, an inner tubularmember sealed therein in end-to-end manner, and a solar energycollecting agent sealedly provided between said outer and inner tubularmembers, wherein said water conduit is formed between said inner tubularmember and said heat transferring tube such that said solar energycollecting agent is adapted for collecting said solar energy to heat upsaid water within said inner tubular member.
 6. The solar energy waterheater, as recited in claim 3, further comprising a heat insulatinglayer enclosing an outer surface of said water pipe for preventing heatloss of said water passing along said water passage.
 7. The solar energywater heater, as recited in claim 5, further comprising a heatinsulating layer enclosing an outer surface of said water pipe forpreventing heat loss of said water passing along said water passage. 8.The solar energy water heater, as recited in claim 1, wherein said solarheat units are formed in pairs that each pair of said solar heat unitsare transversely and opposedly extended from said water pipe tocommunicate with said water passage, wherein said water is guided toflow from said water inlet to said water outlet through each pair ofsaid solar heat units in a zigzag manner.
 9. The solar energy waterheater, as recited in claim 8, wherein said two heat transferring tubesof each pair of said solar heat units are integrally extended to form anelongated tubular structure through said water pipe so as to communicatesaid water channels with each other.
 10. The solar energy water heater,as recited in claim 8, further comprising a plurality of water guidersspacedly disposed in said water passage of said water pipe to align withsaid pairs of solar heat units respectively, wherein each of said waterguiders has a guiding passage extended to said inner opened end of oneof said heat collecting tubes for guiding said water to flow into saidrespective water conduit of each pair of said solar heat units.
 11. Thesolar energy water heater, as recited in claim 9, further comprising aplurality of water guiders spacedly disposed in said water passage ofsaid water pipe to align with said pairs of solar heat unitsrespectively, wherein each of said water guiders has a guiding passageextended to said inner opened end of one of said heat collecting tubesfor guiding said water to flow into said respective water conduit ofeach pair of said solar heat units.
 12. The solar energy water heater,as recited in claim 8, wherein each of said heat collecting tubecomprises an outer tubular member, an inner tubular member sealedtherein in end-to-end manner, and a solar energy collecting agentsealedly provided between said outer and inner tubular members, whereinsaid water conduit is formed between said inner tubular member and saidheat transferring tube such that said solar energy collecting agent isadapted for collecting said solar energy to heat up said water withinsaid inner tubular member.
 13. The solar energy water heater, as recitedin claim 11, wherein each of said heat collecting tube comprises anouter tubular member, an inner tubular member sealed therein inend-to-end manner, and a solar energy collecting agent sealedly providedbetween said outer and inner tubular members, wherein said water conduitis formed between said inner tubular member and said heat transferringtube such that said solar energy collecting agent is adapted forcollecting said solar energy to heat up said water within said innertubular member.
 14. The solar energy water heater, as recited in claim11, further comprising a heat insulating layer enclosing an outersurface of said water pipe for preventing heat loss of said waterpassing along said water passage.
 15. The solar energy water heater, asrecited in claim 13, further comprising a heat insulating layerenclosing an outer surface of said water pipe for preventing heat lossof said water passing along said water passage.
 16. The solar energywater heater, as recited in claim 1, wherein said solar heat units areformed in pairs that each pair of said solar heat units are transverselyand opposedly extended from said water pipe to communicate with saidwater passage, wherein said water is guided to flow from said waterinlet to said water outlet through each pair of said solar heat units ina splitting manner.
 17. The solar energy water heater, as recited inclaim 16, further comprising a plurality of water guiders spacedlydisposed in said water passage of said water pipe to align with saidpairs of said solar heat units respectively, wherein each of said waterguiders, having a T-shape, has two guiding passages communicativelyextended to two inner ends of said heat transferring tubes respectivelyfor guiding said water to flow from said water passage into said waterchannels.
 18. The solar energy water heater, as recited in claim 17,wherein each of said water guiders has a guiding splitter disposedwithin said water passage for evenly dividing said water therewithininto two portions to flow into said respective pair of said solar heatunits.
 19. The solar energy water heater, as recited in claim 16,wherein each of said heat collecting tube comprises an outer tubularmember, an inner tubular member sealed therein in end-to-end manner, anda solar energy collecting agent sealedly provided between said outer andinner tubular members, wherein said water conduit is formed between saidinner tubular member and said heat transferring tube such that saidsolar energy collecting agent is adapted for collecting said solarenergy to heat up said water within said inner tubular member.
 20. Thesolar energy water heater, as recited in claim 18, wherein each of saidheat collecting tube comprises an outer tubular member, an inner tubularmember sealed therein in end-to-end manner, and a solar energycollecting agent sealedly provided between said outer and inner tubularmembers, wherein said water conduit is formed between said inner tubularmember and said heat transferring tube such that said solar energycollecting agent is adapted for collecting said solar energy to heat upsaid water within said inner tubular member.
 21. The solar energy waterheater, as recited in claim 18, further comprising a heat insulatinglayer enclosing an outer surface of said water pipe for preventing heatloss of said water passing along said water passage.
 22. The solarenergy water heater, as recited in claim 20, further comprising a heatinsulating layer enclosing an outer surface of said water pipe forpreventing heat loss of said water passing along said water passage. 23.A method of heating water through a solar energy water heater whichcomprises a water pipe and a plurality of solar heat units transverselyand spacedly extended therefrom, each said solar heat units comprising aheat collecting tube and a heat transferring tube which is made of heatconductive material disposed therein, wherein said method comprises thesteps of: (a) guiding said water to flow into a water inlet of saidwater pipe to each of said solar heat units; (b) guiding said water toflow into a water channel of said heat transferring tube from an innerend of said heat transferring tube towards an outer opening end thereofso as to heat up said water along said water channel, wherein said innerend of said heat transferring tube is extended from said water pipe tocommunicate said water channel with said water pipe; (c) guiding saidwater to flow into a water conduit from said outer opening end of saidheat transferring tube to heat up said water along said water conduit,wherein said water conduit is formed between said heat collecting tubeand said heat collecting tube, wherein said outer opening end of saidheat transferring tube is extended towards to an outer closed end ofsaid heat collecting tube to communicate said water channel with saidwater conduit of said heat collecting tube; (d) guiding said water toflow into said water pipe from an inner opened end of said heatcollecting tube, wherein said inner opened end of said heat collectingtube is extended from said water pipe to communicate said water conduitwith said water pipe; and (e) guiding said water to flow out of saidwater pipe at a water outlet thereof.
 24. The method, as recited inclaim 23, wherein said solar heat units are formed in pairs that eachpair of said solar heat units are transversely and opposedly extendedfrom said water pipe to communicate with said water passage, wherein, instep (b), said water is split into two portions to respectively flowinto said water channels of said heat transferring tubes of said pair ofsaid solar heat units.
 25. The method, as recited in claim 23, whereineach of said heat collecting tube comprises an outer tubular member, aninner tubular member sealed therein in end-to-end manner, and a solarenergy collecting agent sealedly provided between said outer and innertubular members, wherein said water conduit is formed between said innertubular member and said heat transferring tube such that said solarenergy collecting agent is adapted for collecting said solar energy toheat up said water within said inner tubular member.
 26. The method, asrecited in claim 24, wherein each of said heat collecting tube comprisesan outer tubular member, an inner tubular member sealed therein inend-to-end manner, and a solar energy collecting agent sealedly providedbetween said outer and inner tubular members, wherein said water conduitis formed between said inner tubular member and said heat transferringtube such that said solar energy collecting agent is adapted forcollecting said solar energy to heat up said water within said innertubular member.